Apparatus for cooling well surveying instruments



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B. E. RICHERT Filed March 15, 1951 March 9, 1954 A INVENTOR. BERNHARD E. R/CHET M, e www Patented Mar. 9, 1954 APPARATUS Fon cooLING WELL i sURvEYxNG INSTRUMENTS Bernhard E; Richert, BeaumongTex., assigner to Sun Oil Company, Philadelphia, Pa., a corporation of New Jersey Application Maren 15, 1951, serial No. 215,760

(ci. isz-125') 2 Claims. l

Thisnvention relates to apparatus for coolingy well surveying instruments and, more particularly, to apparatus which may be included with a well surveying instrument within a protective casing when the instrument is lowered withina bore hole in order to cool the instrument. Diiculty is frequently encountered in the opr eration of well surveying instruments-within a. bore hole as a result of relatively hightemper-:Yy i atures existing within the bore hole when the operation of the instrument is dependent upon apparatus whichis aifected by heat such as,- for example, photographic plates, batteries, chemicals and accurately ntted or aligned parts which.

as a result of expansion occurring at elevated temperatures, fail-to function properly as a re sult of misalignxnent.

Cooling'apparatust'o be suitable for application with instruments lowered into a bore-hole mustbe compact in nature and. to a reasonable degree;-selfcontrolled.

Itis `an object of the present invention to proi vide apparatus for. cooling a. well surveying in-v strument which may be placed within the proteetive casing containing the well surveying in strument.

portion of that instrument as may be desired.

These and other objects of the invention will become apparent from the following description boiling alcohols.

when read in conjunction with the accompanying drawing, in which: A

Figure 1 is an elevation in section showing a protective casing for a well surveying instrument within which is'mounted one form of the present invention;

Figure 2 is a transverse section taken on the plane 2 2 of Figure 1; and

Figure 3 is an elevation partly in section showing an alternate form of the present invention.

Referring to Figures 1 and 2 there is shown a protective casing such as would normally house a well surveying instrument. Within the casing there is a heatinsulating lining 2 surroundingr a well surveying instrument, `the outline of which is shown by construction lines 4. The insulating lining may extend a suitable distance above and below the cooling apparatuswhich is hereinafter described. As previously mentioned, the r v' nstrurnent maybe any one of a variety of well surveying instruments `well known in the art which would desirably have a portion thereof cooled. Within the insulating lining 2 and above the instrument 4 there is @NN g,

-coils I2.

chemical mixture, a fusing solid, such as ice or a' frozen liquid, ora material such as solid carbon dioxide and a carbon dioxide gas absorbing ---chemical. -If this latter cooling medium were used, a separate vessel connected to the retainer 5 would desirably be provided for retaining the lcarbon dioxide gas absorbing chemical. These and other cooling media such as are well known to the cooling art. may be employed within the cooling medium retainer 6. i

Mounted within the coolingmedium retainer is the condensing chamber IIJ.v Surrounding a portion of the well surveying instrument 4 are the The .coils are lled for a portion of their. depth Vwith a suitable liquid I4. This liquid may be any liquid which will boil at the temperatures involved, and maybe selected to have a boiling point such as to control a temperature of the portion of the well surveying apparatus adjacent thereto at anyA predetermined value. This liquid may be, by way of example, acetonei ether chloroform r one of the lower The upper portion of the coil is connec e by means of the tube I6 to the condensing chamber Ill.l The lower portion of the coil I2 is connected to the lower portion of the condensing chamber I0 by means of the tube Heat from the surveying instrument passing through the walls of thecoil I2 will heat the liq-v uid I4 causing it to boil. The vapors rising from the boiling liquid will pass through line I5 into the condensing chamber ID. The vapor will condense Within the condensing chamber due to the reduced temperature of the chamber as will be maintained by the cooling medium within the retainer E, the vapor givingV up its heat to the cooling medium. The'condensate forming in the condensing chamber In will pass downwardly through line I8 to the coils I2 wherein it will again pick up heat from the well surveying in-A strument. This cycle will provide an effective heat transfer between the well surveying instrument and the cooling medium in the retainer. the latentv heat of vaporization being employed in this cycle, which includes a change of phase of the heat conveying material, to provide a heat transfer rate greatly in excess of that which could be accomplished by merely circulating a liquid in passages of similar size to those employed herein. y

It will be apparent that.' by selecting liquids oi be controlled by establishing the initial pressure within the system such as to give rise to a predetermined boiling temperature of the particular liquid employed. The tube I I is connected to the condensing chamber Il! and is provided with a sealing cap I3. This tube is provided to permit changing of the liquid in the system and to provide means through which the pressure oi the system may be adjusted.

In Figure 3 there is shown a modied form of the invention employing within a protective casing 2| and an insulating lining 22 a well surveying instrument shown in outline 24. Above the instrument there is mounted a cooling medium retainer 26 which is provided with a cover 28 and contains cooling medium 29. To this extent the apparatus in Figure 3 is identical to that shown in Figure 1.

In the form oi' the device shown in Figure 3 the boiler is in the form of an annular vessel 3|, connected to the lower end of a tubular member 3U, which contains in its lower portion a pool of liquid 32 which may be any suitable liquid such as previously described. Mounted within the cooling medium retainer is the condenser 3l. The upper end oi the tubular member 30 is connected to the lower portion of the condenser 34.

In `this form of the invention the liquid 32 vaporizes, as a result of heat passing from the well surveying instrument 2l, into the liquid and vapors rising from the liquid pass upwardly through the tube 3U into the condensing chamber 34 wherein the vapor condenses on the cooled walls of the condensing chamber and the condensate ows downwardly through the tube 30 into theV pool of liquid 32 contained in the lower portion thereof. In this form of the invention, heat absorption from the adjacent portion of the well surveying instrument may be provided by the sublimation of a solid contained in the vessel 3l. It will be apparent that the form of the invention shown in Figure 1 may be modied by including in piace of the coils I2 an annular container,

such as is shown in Figure 3, to form the boiler to which the tubes I8 and Il may be connected for communication with the condensing chamber.

By means ot this device there is provided a simple and effective cooling apparatus which may be employed to cool substantially any desired portion or a well surveying instrument within a protective casing.

What is claimed is:

1. Apparatus adapted to pass downwardly into a bore hole. said apparatus comprising a casing. a heat insulating lining within said casing, a well surveying instrument mounted within said casing, a boiler disposed adjacent to the weil surveying instrument and containing a liquid, the liquid in said boiler being heated by heat from the surveying instrument, a container positioned above said boiler and said instrument within said lining, a condensing chamber mounted within said container, a cooling medium within said container cooling said condensing chamber, and means for carrying vapor rising from the liquid in said boiler upwardly` to said condensing chamber and for carrying condensate forming in said conde chamber downwardly to said boiler.

2. Apparatus adapted to pass downwardly into a bore hole. said apparatus comprising a casing, a heat insulating lining within said easing, a well surveying instrument mounted within said casing. a generally annular boiler comprising a member surrounding aportion oi' the well surveying instrument and -containing a liquid, the liquid in said boiler being heated by heat from the surveying instrument, a container positioned above said boiler and said instrument within said lining. a condensing chamber mounted within said container, a. cooling medium within said container cooling said condensing chamber, and means i'or carrying vapor rising i'rom the liquid in said boiler upwardly to said condensing chamber and for carrying condensate forming in said condensing chamber downwardly to said boiler.

BERNHARD E. RICHERT.

References Cited in the le oi this patent UNITED STATES PATENTS Number Name Date 1,843,026 Hunt Jan. 26, 1932 1,875,293 Schlumbohm Aug. 30, 1932 1,975,868 Schlumbohm Oct. 9, 1934 2,044,609 Hedlund June 16, 1930 2,324,103 'Miller July 13, 1943 

